Lamp House and projector device thereof

ABSTRACT

A lamp house for appropriately preventing danger when a lamp bulb breaks up includes, at a vent hole for cooling the lamp bulb as a light source provided in a housing, a movable plate which is movable only toward the inside of the housing of the lamp house, a spring for closing the movable plate and a sensor for detecting opening and closing states of the movable plate disposed on the side of an air inlet of the vent hole.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a lamp house, and moreparticularly, to a lamp house which makes a lamp having high-pressuregas filled therein emit light and a projector device thereof.

[0003] 2. Description of the Related Art

[0004] Lamp house is a housing in which a discharge lamp is attached formaking the lamp with high-pressure gas such as mercury and xenon filledtherein emit light. Light emission from a discharge lamp provided in alamp house is for use as a light source for experiments, that for aninstrument for analysis, that for printing a semiconductor, that for afluorescence microscope, that for a blood analyzer, that for curingultraviolet rays, and that for projecting picture and as aninterferometer, a refractometer, and a microfilm enlargement device. Inaddition, for use as a light source for these purposes, the lamp houseis often used attached to a projector device which conductsfloodlighting, projecting and profile projecting for relevant purposes.

[0005] Also, since a discharge lamp as a light source generates greatheat (e.g. higher than 700 degrees centigrade of a surface temperature)and has high-pressure gas filled therein (e.g. about 10 atmospheres atroom temperature and 40 atmospheres at operation), if the lamp breaks upfor some reason or other, it is very dangerous.

[0006] Lamp house therefore has a function of housing a discharge lampas a light source to emit light, thereby preventing danger at the timeof break-up, as well as preventing overheat of the discharge lamp bycooling the lamp by directing outside air. Moreover, being provided in alamp house, a discharge lamp is prevented from breakage due tomechanical shock and being cooled, the lamp will have its deteriorationsuppressed to maintain brightness and life.

[0007]FIG. 10 is a perspective view showing a structure of conventionallamp house id and projector device 2 d.

[0008] With reference to FIG. 10, the lamp house Id has in its housing alamp bulb 40 as a light source attached and a reflector 33 providedaround the lamp bulb for reflecting and converging light, therebyconverging light toward a window 70 to emit light to the outside of thelamp house id. For the window 70, dissolved quartz (fused quartz) or thelike having a high ultraviolet ray transmissibility is used.

[0009] Also provided, as a ventilating hole for cooling the lamp bulb40, are two openings, an air inlet 10 and an air outlet 20.

[0010] The lamp house id directs outside air sent from a sirocco fan 18of the projector device 2 d from the air inlet 10 to the lamp bulb 40 tocool the same and externally exhausts the air heated inside the lamphouse 1 d through the air outlet 20.

[0011] The air inlet 10 and the air outlet 20 as the openings of thelamp house 1 d are covered with metal meshes 19 and 29 (wire netting) toprevent broken pieces generated when the lamp bulb 40 breaks up fromgoing outside. The metal meshes 19 and 29 prevent relatively largefragments from scattering outside the device.

[0012] Also provided is a static pressure meter 50 which detects adifference between external and internal pressures of the lamp house 1 din order to check whether the lamp bulb 40 is currently being cooled byventilation from the sirocco fan 18.

[0013] The higher the temperature becomes, the higher a possibility ofbreak-up of the lamp bulb 40 becomes to enhance a deterioration rate andshorten life. Therefore, check whether the bulb is being cooled or notto avoid this danger.

[0014] When the lamp bulb 40 is being cooled, a large difference isgenerated between internal and external pressures of the lamp house 1 dbecause air is sent into the lamp house id at high pressure for coolingthe lamp bulb 40, so that measuring the pressure difference by thestatic pressure meter 50 leads to determination whether the lamp bulb isbeing cooled or not.

[0015] The static pressure meter 50 for checking the cooling isconnected to a control circuit or the like of the projector device 2 d,which control circuit executes such processing of starting ventilation,stopping light emission (to stop power transmission to the lamp bulb 40)and notifying a user when there is no ventilation, thereby preventingoverheating of the lamp bulb 40.

[0016] Inside the air inlet 10, attached is a guide metallic part 60 forappropriately setting a position at which cooling air from the siroccofan 18 hits in order to execute cooling of the lamp bulb 40 at anappropriate part.

[0017] The lamp bulb 40 has its cap parts 41 and 42 cooled (e.g. 200degrees centigrade or less) for maintaining brightness and life and hasits central part emitting a light maintained at a high temperature (e.g.750 degrees centigrade or less). Accordingly, in the lamp house Id, theguide metallic part 60 provided therein targets a part at whichventilation from the air inlet 10 hits at the cap parts 41 and 42 tointensively cool the cap parts.

[0018] In a conventional lamp house, an opening for cooling a lamp bulbis thus open all the time. Even if the openings are covered with themetal meshes 19 and 29, small broken pieces might scatter to the outsideof the lamp house. In addition, a static pressure meter for checkingwhether a lamp bulb is being cooled is expensive.

[0019] As described in the foregoing, conventional lamp houses have thefollowing problems.

[0020] First, because an opening is open all the time, when a lamp bulbbreaks up, there is danger of scattering of broken pieces to the outsideof the lamp house through a space between metal meshes covering theopening and the like.

[0021] Secondly, an expensive static pressure meter is necessary todetect whether ventilation is conducted to cool a lamp bulb.

[0022] Thirdly, a guide metallic part should be specially provided forappropriately directing ventilation.

SUMMARY OF THE INVENTION

[0023] First object of the present invention is to provide a lamp housewhich appropriately prevents danger in a case of break-up of a lamp bulband efficiently cools the lamp bulb, and a projector device thereof.

[0024] Second object of the present invention is to provide a lamp houserealizing a function of detecting whether cooling is conducted or not bya simple structure manufacturable at low costs without requiring anadvanced function such as a static pressure meter and a projector devicethereof.

[0025] Third object of the present invention is to provide a lamp houseenabling a unit for adjusting a direction of ventilation for cooling alamp bulb to be effectively structured and a projector device thereof.

[0026] According to one aspect of the invention, a lamp house comprises,

[0027] at a vent hole for cooling a light source provided in a housingby ventilation, a movable plate which is movable only toward the insideof the housing.

[0028] In the preferred construction, the movable plate is attached tothe inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate, and

[0029] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight.

[0030] In another preferred construction, when the lamp house isattached to a projector device,

[0031] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and

[0032] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet.

[0033] In another preferred construction, the movable plate is attachedto the inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate,

[0034] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight, and

[0035] when the lamp house is attached to the projector device, themovable plate disposed on the side of an air inlet of the vent holeopens inwardly upon receiving ventilation from the projector device,

[0036] and the movable plate disposed on the side of an air outlet ofthe vent hole opens upon insertion of a duct of the projector deviceinto the housing through the air outlet.

[0037] In another preferred construction, when the lamp house isattached to a projector device,

[0038] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and

[0039] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet,

[0040] and which further comprises a spring for closing the movableplate, wherein

[0041] when the lamp house is not attached to the projector device, thespring closes the movable plate irrespective of the position of thehousing, and

[0042] the spring attached to the movable plate on the side of the airinlet of the vent hole opens the movable plate inwardly upon receivingventilation from the projector device.

[0043] In another preferred construction, the movable plate is attachedto the inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate,

[0044] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight, and

[0045] when the lamp house is attached to the projector device, themovable plate disposed on the side of an air inlet of the vent holeopens inwardly upon receiving ventilation from the projector device, and

[0046] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet,

[0047] and which further comprises a spring for closing the movableplate, wherein

[0048] when the lamp house is not attached to the projector device, thespring closes the movable plate irrespective of the position of thehousing, and

[0049] the spring attached to the movable plate on the side of the airinlet of the vent hole opens the movable plate inwardly upon receivingventilation from the projector device.

[0050] In another preferred construction, when the lamp house isattached to a projector device,

[0051] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and the movable plate disposed on the side of an air outlet ofthe vent hole opens upon insertion of a duct of the projector deviceinto the housing through the air outlet,

[0052] and which further comprises a sensor for detecting opening andclosing states of the movable plate disposed on the side of the airinlet of the vent hole.

[0053] In another preferred construction, the movable plate is attachedto the inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate,

[0054] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight, and

[0055] when the lamp house is attached to the projector device, themovable plate disposed on the side of an air inlet of the vent holeopens inwardly upon receiving ventilation from the projector device, and

[0056] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet,

[0057] and which further comprises a sensor for detecting opening andclosing states of the movable plate disposed on the side of the airinlet of the vent hole.

[0058] In another preferred construction, when the lamp house isattached to a projector device,

[0059] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and

[0060] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet,

[0061] and which further comprises a spring for closing the movableplate, wherein

[0062] when the lamp house is not attached to the projector device, thespring closes the movable plate irrespective of the position of thehousing, and

[0063] the spring attached to the movable plate on the side of the airinlet of the vent hole opens the movable plate inwardly upon receivingventilation from the projector device, and

[0064] a sensor for detecting opening and closing states of the movableplate disposed on the side of the air inlet of the vent hole.

[0065] In another preferred construction, the movable plate is attachedto the inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate,

[0066] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight, and

[0067] when the lamp house is attached to the projector device,

[0068] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and

[0069] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet,

[0070] and which further comprises a spring for closing the movableplate, wherein

[0071] when the lamp house is not attached to the projector device, thespring closes the movable plate irrespective of the position of thehousing, and

[0072] the spring attached to the movable plate on the side of the airinlet of the vent hole opens the movable plate inwardly upon receivingventilation from the projector device, and

[0073] a sensor for detecting opening and closing states of the movableplate disposed on the side of the air inlet of the vent hole.

[0074] In another preferred construction, using the movable platedisposed on the side of an air inlet of the vent hole, an air path, inthe lamp house, of ventilation received from the projector device isset.

[0075] In another preferred construction, the movable plate is attachedto the inner side of the side surface of the housing by means of a hingeprovided at the upper part of the movable plate,

[0076] when the lamp house is not attached to a projector device, themovable plate closes because of its own weight, and

[0077] using the movable plate disposed on the side of an air inlet ofthe vent hole, an air path, in the lamp house, of ventilation receivedfrom the projector device is set.

[0078] In another preferred construction, when the lamp house isattached to a projector device,

[0079] the movable plate disposed on the side of an air inlet of thevent hole opens inwardly upon receiving ventilation from the projectordevice, and

[0080] the movable plate disposed on the side of an air outlet of thevent hole opens upon insertion of a duct of the projector device intothe housing through the air outlet, and which further comprises a springfor closing the movable plate, wherein

[0081] when the lamp house is not attached to the projector device, thespring closes the movable plate irrespective of the position of thehousing, and

[0082] the spring attached to the movable plate on the side of the airinlet of the vent hole opens the movable plate inwardly upon receivingventilation from the projector device, and

[0083] using the movable plate disposed on the side of the air inlet ofthe vent hole, an air path, in the lamp house, of ventilation receivedfrom the projector device is set.

[0084] In another preferred construction, the vent hole includes aplurality of air inlets.

[0085] According to another aspect of the invention, a projector deviceto which a lamp house is attached,

[0086] the lamp house comprises,

[0087] at a vent hole for cooling a light source provided in a housingby ventilation, a movable plate which is movable only toward the insideof the housing.

[0088] In the preferred construction, the projector device comprises aduct for externally discharging exhaust air from the lamp house, wherein

[0089] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing.

[0090] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0091] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing, and

[0092] the duct has an exhaust air outlet for discharging exhaust airfrom the lamp house whose area is larger than a sectional area of eachpart of the duct and has the exhaust air outlet covered with wirenetting.

[0093] In another preferred construction, the projector device furthercomprises ventilation means for ventilating the lamp house, wherein

[0094] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation.

[0095] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0096] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing, and

[0097] ventilation means for ventilating the lamp house, wherein

[0098] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation.

[0099] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0100] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing, and

[0101] the duct has an exhaust air outlet for discharging exhaust airfrom the lamp house whose area is larger than a sectional area of eachpart of the duct and has the exhaust air outlet covered with wirenetting, and ventilation means for ventilating the lamp house, wherein

[0102] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation.

[0103] In another preferred construction, the projector device furthercomprises ventilation means for ventilating the lamp house, wherein

[0104] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation, and

[0105] control means for controlling operation of the lamp house,wherein

[0106] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole.

[0107] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0108] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing,

[0109] ventilation means for ventilating the lamp house, wherein

[0110] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation, and

[0111] control means for controlling operation of the lamp house,wherein

[0112] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole.

[0113] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0114] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing, and

[0115] the duct has an exhaust air outlet for discharging exhaust airfrom the lamp house whose area is larger than a sectional area of eachpart of the duct and has the exhaust air outlet covered with wirenetting,

[0116] ventilation means for ventilating the lamp house, wherein

[0117] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation, and

[0118] control means for controlling operation of the lamp house,wherein

[0119] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole.

[0120] In another preferred construction, the projector device furthercomprises ventilation means for ventilating the lamp house, wherein

[0121] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation,

[0122] control means for controlling operation of the Lamp house,wherein

[0123] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole, and

[0124] a sensor for detecting opening and closing states of the movableplate disposed on the side of the air inlet of the vent hole.

[0125] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0126] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing,

[0127] ventilation means for ventilating the lamp house, wherein

[0128] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation,

[0129] control means for controlling operation of the lamp house,wherein

[0130] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole, and

[0131] a sensor for detecting opening and closing states of the movableplate disposed on the side of the air inlet of the vent hole.

[0132] In another preferred construction, the projector device comprisesa duct for externally discharging exhaust air from the lamp house,wherein

[0133] at the time of attachment of the lamp house to the projectordevice, the duct is inserted into the housing through the air outlet toopen the movable plate provided at the air outlet toward the inside ofthe housing, and

[0134] the duct has an exhaust air outlet for discharging exhaust airfrom the lamp house whose area is larger than a sectional area of eachpart of the duct and has the exhaust air outlet covered with wirenetting,

[0135] ventilation means for ventilating the lamp house, wherein

[0136] the ventilation means opens the movable plate disposed on theside of an air inlet of the vent hole toward the inside of the housingby a wind pressure caused at the time of ventilation,

[0137] control means for controlling operation of the lamp house,wherein

[0138] the control means determines whether the light source is beingcooled according to opening and closing states of the movable platedisposed on the side of the air inlet of the vent hole, and

[0139] a sensor for detecting opening and closing states of the movableplate disposed on the side of the air inlet of the vent hole.

[0140] Other objects, features and advantages of the present inventionwill become clear from the detailed description given herebelow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0141] The present invention will be understood more fully from thedetailed description given herebelow and from the accompanying drawingsof the preferred embodiment of the invention, which, however, should notbe taken to be limitative to the invention, but are for explanation andunderstanding only.

[0142] In the drawings:

[0143]FIG. 1 is a perspective view showing a structure of a lamp houseaccording to a first embodiment of the present invention;

[0144]FIG. 2 is a perspective view showing the structure of the lamphouse according to the first embodiment of the present invention;

[0145]FIG. 3 is a perspective view showing the structure of the lamphouse according to the first embodiment of the present invention asattached to a projector device;

[0146]FIG. 4 is a perspective view showing a structure of a movableplate according to the first embodiment of the present invention;

[0147]FIG. 5 is a perspective view showing a structure of a movableplate according to a second embodiment of the present invention;

[0148]FIG. 6 is a perspective view showing a state of a movable plateclosed according to a third embodiment of the present invention;

[0149]FIG. 7 is a perspective view showing a state of the movable plateopened according to the third embodiment of the present invention;

[0150]FIG. 8 is a perspective view showing a state of a movable plateopened according to a fourth embodiment of the present invention;

[0151]FIG. 9 is a perspective view showing a structure of a lamp houseaccording to the fourth embodiment of the present invention as attachedto a projector device;

[0152]FIG. 10 is a perspective view showing a structure of aconventional lamp house as attached to a projector device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0153] The preferred embodiment of the present invention will bediscussed hereinafter in detail with reference to the accompanyingdrawings. In the following description, numerous specific details areset forth in order to provide a thorough understanding of the presentinvention. It will be obvious, however, to those skilled in the art thatthe present invention may be practiced without these specific details.In other instance, well-known structures are not shown in detail inorder to unnecessary obscure the present invention.

[0154]FIG. 1 is a perspective view showing a structure of a lamp house 1according to a first embodiment of the present invention, FIG. 2 is aperspective view showing a structure of the inside of the lamp house 1according to the present embodiment, and FIG. 3 is a perspective viewshowing the structure of the lamp house 1 according to the presentembodiment as attached to a projector device 2.

[0155] With reference to each of FIGS. 1, 2 and 3, the lamp house 1 ofthe present embodiment has, inside its housing 100, a lamp bulb 40 as alight source attached and a reflector 33 provided around the lamp bulbfor reflecting and converging light, thereby converging light toward awindow 70 to emit light to the outside of the lamp house 1.

[0156] Although in the present embodiment, the lamp house 1 in which thelamp bulb 40 is disposed horizontally as shown in the figures will bedescribed as an example, the lamp house is not limited to the presentsystem and the present invention as will be described in the followingcan be embodied in the same manner by the lamp bulb 40 disposedvertically. Furthermore, although in the example shown in each figure,an anode cap part 42 of the lamp bulb 40 is attached facing thereflector 33 side and a cathode cap part 41 is attached facing thewindow 70 side, they may be attached facing either side.

[0157] With reference to FIGS. 1 and 3, the lamp house 1 according tothe present embodiment is provided with an air inlet 10 and an airoutlet 20 as cooling openings and inside the respective openings,movable plates 11 and 21 are arranged, respectively.

[0158] When the lamp house 1 is disposed at the projector device 2, theair inlet 10 is arranged at a position to which an outlet of a siroccofan 18 of the projector device 2 attaches and the air outlet 20 isarranged at a position to which an exhaust port of a duct 28 of theprojector device 2 attaches.

[0159] With this arrangement, the lamp house 1 receives outside air sentfrom the sirocco fan 18 of the projector device 2 through the air inlet10 and directs the air concentratedly to the cap parts 41 and 42 of thelamp bulb 40 to cool the same and discharge air heated inside the lamphouse 1 d to the outside of the lamp house through the air outlet 20.

[0160]FIG. 4 is a perspective view showing a structure of the movableplate 11 on the side of the air inlet 10 according to the presentembodiment, which structure is the same as that of the movable plate 21on the side of the air outlet 20.

[0161] As shown in FIG. 4, the movable plate 11 on the side of the airinlet 10 and the movable plate 21 on the side of the air outlet 20 areattached to the inner side of the side surface of the housing 100 of thelamp house 1 by a hinge 12. The movable plates 11 and 21 are structuredto open only toward the inside of the housing 100 of the lamp house 1and when no external force is applied to the movable plates 11 and 21(i.e. the lamp house 1 is not disposed at the projector device 2), themovable plates 11 and 21 are closed because of their weight.

[0162] Therefore, when the lamp house 1 is detached from the projectordevice 2, all the openings (the air inlet 10 and the air outlet 20) ofthe lamp house 1 are closed and besides, the movable plates 11 and 21shutting the openings are designed to open only inwards, so that whenthe internal lamp bulb 40 breaks up for some reason or other, theopenings remain closed to prevent broken pieces from scattering to theoutside of the lamp house 1.

[0163] It is assumed here that although the lamp bulb 40 in the lamphouse 1 is at a high pressure, the lamp house 1 has a strength enoughfor standing up to breakup of the lamp bulb 40 provided therein, so thatthe lamp house 1 will neither be deformed nor break up to do harm to auser as a result of break-up of the lamp bulb 40. This is because sincethe volume of the lamp bulb 40 is extremely smaller than that of theentire lamp house 1, the inside of the lamp house 1 will not attain adangerously high pressure due to break-up of the lamp bulb 40 and alsobecause for closing the lamp house 1 to prevent broken pieces fromscattering to the outside of the lamp house, complete closing is notalways necessary and it is possible to provide a crevice or a hole sothat gas of the breaking up lamp bulb 40 escapes from the lamp house 1(safely).

[0164] In addition, the movable plates 11 and 21 for closing the airinlet 10 and the air outlet 20, at the operation for making the lampbulb 40 emit light, open toward the inside of the lamp house 1 forventilation and cooling as will be described in the following.

[0165] The movable plate 11 on the side of the air inlet 10, when thelamp bulb 40 emits light, receives a wind pressure of outside air sentfrom the sirocco fan 18 of the projector device 2 to automatically opentoward the inside of the lamp house 1. As a result, the ventilation fromthe sirocco fan 18 enters the lamp house 1 through the air inlet 10 tocool the lamp bulb 40.

[0166] At the time of attaching the lamp house 1 to the projector device2, the movable plate 21 on the side of the air outlet 20 is pushed up bythe duct 28 of the projector device 2 inserted into the air outlet 20from outside to open the air outlet 20 because of a structure of each ofthese devices. As a result, air heated by heat from the lamp bulb 40 canbe discharged outside the lamp house 1 through the air outlet 20 bycooling.

[0167] In addition, for checking whether the lamp bulb 40 is currentlybeing cooled receiving ventilation from the sirocco fan 18 or not, astatic pressure meter 50 for detecting a difference between an internalpressure and an external pressure of the lamp house 1 is provided. Theinside of the lamp house 1 and the static pressure meter 50 areconnected through a tube 51.

[0168] The static pressure meter 50 checks whether cooling is conductedor not by measuring a difference between an internal pressure and anexternal pressure of the lamp house 1 caused by the lamp bulb 40.

[0169] The static pressure meter 50 for checking cooling is connected toa control circuit or the like of the projector device 2 and when noventilation is conducted, the control circuit executes such processingas starting ventilation, stopping light emission (stopping power supplyto the lamp bulb 40) and notifying to a user to prevent overheating ofthe lamp bulb 40.

[0170] The duct 28 has its air outlet side covered with a metal mesh 29a (wire netting) to prevent broken pieces generated when the lamp bulb40 breaks up from scattering to the outside of the projector device 2.

[0171] The duct 28 has its opening designed to be wider at the outlet ofthe projector device 2 (on the air outlet side of the duct 28) on whichside the metal mesh 29 a is attached. Attaching the metal mesh 29 a notto the side of the lamp house 1 whose area is smaller but to the airoutlet side whose area is wider allows an area through which air canpass within the duct 20 to be wider to improve cooling efficiency.

[0172] Although in the embodiment shown in FIGS. 1, 2 and 3, both theair inlet 10 and the air outlet 20 have small areas, even they havewider areas, the above-described effects can be obtained by similarlydisposing the movable plates 11 and 21 of the present embodiment at eachopening of the air inlet 10 and the air outlet 20. Making an area ofeach opening be small, however, enables a wind speed per volume ofoutput of the ventilation device (sirocco fan 18) in front of eachopening to be increased and providing each opening in front of the capparts 41 and 42 which are parts of the lamp bulb 40 to be especiallyintensively cooled achieves efficient cooling.

[0173] Moreover, inside the lamp house 1, a guide metallic part 60 isprovided and by directing ventilation from the sirocco fan 18 taken inthrough the air inlet 10 to the guide metallic part 60, the direction ofthe ventilation can be targeted on the cap part of the lamp bulb 40 tolocally and intensively cool the same.

[0174] With the guide metallic part 60 shown in FIGS. 1, 2 and 3,ventilation from the sirocco fan 18 is divided into two, one turning tothe direction led by the guide metallic part 60 to cool the anode cappart 42 and the other going straight without turning to cool the cathodecap part 41, thereby cooling both the cap parts.

[0175] Next, second embodiment of the present invention will bedescribed in detail with reference to the drawings.

[0176] There will be a case where the projector device 2 is attached toa ceiling upside-down as an installation state and the lamp house 1might as a single body be turned upside down or laid sideways. In such acase, in the lamp house 1 of the first embodiment, since the movableplates 11 and 21 are closed only because of their own weight, they mayopen in the above states and there is danger of scattering of brokenpieces to the outside of the lamp house which are generated by breakupof the lamp bulb 40. In the present embodiment, by pressing movableplates 11 a and 21 a by a spring 14, the movable plates 11 a and 21 aare made not to open even in such a case to realize safety during thework of attaching the lamp house to the projector device 2 and othertime. Also when the lamp bulb 40 emits light, open each of the movableplates 11 a and 21 a with ease to cool the lamp bulb 40 similarly to thefirst embodiment.

[0177]FIG. 5 is a perspective view showing a structure of the movableplate 11 a of a lamp house 1 a according to the second embodiment of thepresent invention.

[0178] With reference to FIG. 5, the difference of the lamp house 1 a ofthe present embodiment from its counterpart in the first embodiment isthat the movable plates 11 a and 21 a disposed at the respectiveopenings of the air inlet 10 and the air outlet 20 are provided with thespring 14 for making the movable plates 11 a and 21 a be closed so asnot to open.

[0179] The spring 14 is assumed to have such a strength that the movableplates 11 a and 21 a will not open due to their own weight and to openwith ease by wind pressure of the sirocco fan 18. Because the movableplates 11 a and 21 a are small in area and light in weight and on theother hand the sirocco fan 18 generates a high wind pressure, theabove-described opening and closing operation can be realized byappropriately setting the strength of the spring 14.

[0180] In addition to the effects attained by the first embodiment,since the foregoing described present embodiment is structured to havethe spring 14 press the movable plates 11 a and 21 a provided at theopenings of the lamp house 1, when the lamp house is not attached to theprojector device 2, the movable plates 11 a and 21 a are allowed toremain closed irrespective of an installation direction and installationsituations, thereby achieving safety while maintaining easiness ofattachment of the lamp house 1 a to the projector device 2.

[0181] Next, third embodiment of the present invention will be describedin detail with reference to the drawings.

[0182] In the present embodiment, determination whether the lamp bulb 40is being cooled or not is made by detecting opening and closing statesof a movable plate 11 b disposed at the air inlet 10 without requiringthe static pressure meter 50.

[0183]FIG. 6 is a perspective view showing a state of the movable plate11 b closed according to the present embodiment, while FIG. 7 is aperspective view showing a state of the movable plate 11 b openaccording to the present embodiment.

[0184] With reference to each of FIGS. 6 and 7, the difference of a lamphouse lb of the present embodiment from its counterpart in the secondembodiment is that a switch for determining whether the movable plate 11b disposed at the air inlet 10 is open or closed is provided and in theexample shown in each of the figures, two switches, a first switch 15and a second switch 16 are provided.

[0185] Each of the switches 15 and 16, similarly to the static pressuremeter 50 of the first and second embodiments, is connected to a controlcircuit of a projector device 2 b to inform the control circuit whetherthe lamp bulb 40 is being cooled or not.

[0186] The movable plate 11 b is L-shaped with the hinge 12 providedin-between as shown in each figure and the first switch 15 is turned“OFF” when the movable plate 11 b is open slightly and the second switch16 is turned “ON” when the same is open further.

[0187] In FIG. 6, the movable plate 11 b is closed without receivingventilation from the sirocco fan 18, so that the first switch 15disposed at the position of the opening of the air inlet 10 is turned“ON” and the second switch 16 disposed on the opposite side of the hinge12 with respect to the air inlet 10 is turned “OFF”. In this case, thecontrol circuit determines that the lamp bulb 40 is not being cooled toexecute predetermined operation which is to be conducted in such a casein a manner as descrribed in the first embodiment.

[0188] In FIG. 7, the movable plate 11 b receives ventilation from thesirocco fan 18 and is opened due to the wind pressure. In this case, thefirst switch 15 is turned “OFF” and the second switch 16 is turned “ON”.As EL result, the control circuit determines that the lamp bulb 40 isbeing cooled and therefore it is safe even light emission of the lampbulb 40 is continued, so that the control circuit does not need tochange the current state.

[0189] Here, for determining whether ventilation exists or not, both ofthe first switch 15 and the second switch 16 are not always necessaryand either one of the switches is enough unless they are speciallyrequired.

[0190] The switch can be disposed not exclusively on the side of thelamp house lb and it can be disposed on the side of the projector device2 b.

[0191] In addition, as long as the switch is capable of detectingopening and closing states of the movable plate 11 b, any switch can beused such as a switch for detecting an angle at which the hinge 12opens.

[0192] As described in the foregoing, the present embodiment does notneed to use an expensive static pressure meter for determining whetherthe lamp bulb 40 is being cooled, and enables such determination withease by detecting the movable plate 11 b at the air inlet 10 beingopened.

[0193] Next, fourth embodiment of the present invention will bedescribed in detail with reference to the drawings.

[0194] In the present embodiment, in place of the guide metallic part 60of the first embodiment, by making use of an angle of the movable plate11 b opened, the direction of outside air sent through the air inlet 10into a lamp house 1 c is faced toward the cap part of the lamp bulb 40to be intensively cooled.

[0195]FIG. 8 is a perspective view showing a movable plate 11 c beingopened according to the fourth embodiment of the present invention.

[0196] With reference to FIG. 8, in the present embodiment, the movableplate 11 c disposed at the air inlet 10 is designed to be L-shaped withthe hinge 12 provided in-between so that the movable plate 11 c opens ata fixed angle.

[0197]FIG. 9 is a perspective view showing a structure of the lamp house1 c according to the fourth embodiment of the present invention asdisposed at the projector device 2.

[0198] The movable plate 11 c is bent to be L-shaped and as illustratedin FIG. 9, an angle of the plate being opened by wind pressure of thesirocco fan 18 can be set in advance. This arrangement enables themovable plate 11 c, in place of the guide metallic part 60 in each ofthe above-described embodiments, to serve as a guide to lead cooling airto the cap part of the lamp bulb 40.

[0199] As described in the foregoing, in the present embodiment, themovable plate 11 c disposed at the air inlet 10 functions as a guide todirect cooling air to the cap part of the lamp bulb 40 to have anadvantage that provision of a guide metallic part conventionallyprovided inside the device is unnecessary.

[0200] Although each of the above embodiments have been described withrespect to an example where only one air inlet 10 is provided, a systemin which the air inlet 10 and the air outlet 20 of the present inventionare provided in the plural inside a lamp house can achieve the sameeffects of preventing danger of break-up of the lamp bulb 40, detectingwhether the bulb is being cooled and appropriately directing ventilationinto the lamp house to cool the cap parts 41 and 42 as those attained bythe above-described respective embodiments. For example, a system inwhich the air inlet 10 in particular is arranged near both of thecathode cap 41 and the anode cap 42 can realize local cooling of boththe cap parts.

[0201] While each of the above embodiments has been described withrespect to a lamp house in which the lamp bulb 40 is horizontallydisposed as an example, the structure of the air inlet 10 and the airoutlet 20 and the cooling system of the lamp bulb 40 as thecharacteristics of the present invention can be similarly realized in alamp house in which the lamp bulb 40 is disposed vertically.

[0202] Similarly, while in each of the above-described embodiments, theanode cap 42 of the lamp bulb 40 is disposed on the side of thereflector 33 and the cathode cap 41 on the side of the window 70, theside on which these caps are arranged is not necessarily limitedthereto. Irrespective of a side on which the anode cap 42 and thecathode cap 41 are disposed and a configuration and a direction of thereflector 33, the structure of the air inlet 10 and the air outlet 20and the cooling system of the lamp bulb 40 as the characteristics of thepresent invention can be realized in the same manner.

[0203] As described in the foregoing, according to the lamp house andthe projector device thereof of the present invention, the followingeffects can be attained.

[0204] First, when a lamp bulb breaks up, scattering of all the brokenpieces including minute pieces to the outside of a lamp house can beprevented to attain a high degree of safety. The reason is that becauseof the movable plate of the present invention provided at an opening ofthe lamp house, when the lamp house is not attached to the projectordevice, the opening is closed.

[0205] Secondly, provision of the movable plate of the present inventioneliminates the need of metal meshes which are conventionally provided toprevent broken pieces generated when a lamp bulb breaks up from goingoutside, thereby increasing a rate of opening to improve coolingefficiency.

[0206] In addition, since metal meshes for preventing broken pieces fromgoing outside during cooling can be disposed outside the lamp house (onthe side of the projector device), by attaching the metal meshes to theoutside to have a large area, a large effective opening area can beensured.

[0207] Thirdly, an expensive static pressure meter for measuring adifference between an internal pressure and an external pressure isunnecessary which is conventionally for use in determining whether alamp bulb is being cooled or not. The reason is that detecting openingand closing states of the movable plate of the present invention enablesdetection whether the lamp bulb is being cooled or not with ease.

[0208] Fourthly, provision of a spring which closes the movable plateallows, when the lamp house is not attached to the projector device, themovable plate to remain closed irrespective of the direction of the lampbulb, thereby reducing danger of scattering of broken pieces to theoutside at the time of break-up to realize a high degree of safety. Thereason is that since some load is required to open the movable platedisposed at the lamp house opening, the movable plate will not be openedeasily depending on installation situations and the like.

[0209] Fifthly, a guide plate conventionally provided for locallycooling a lamp bulb is not necessary. The reason is that the movableplate disposed at an air inlet is allowed to control a flow and adirection of cooling air while maintaining its direction obtained whenopened at cooling.

[0210] Although the invention has been illustrated and described withrespect to exemplary embodiment thereof, it should be understood bythose skilled in the art that the foregoing and various other changes,omissions and additions may be made therein and thereto, withoutdeparting from the spirit and scope of the present invention. Therefore,the present invention should not be understood as limited to thespecific embodiment set out above but to include all possibleembodiments which can be embodies within a scope encompassed andequivalents thereof with respect to the feature set out in the appendedclaims.

What is claimed is:
 1. A lamp house comprising, at a vent hole forcooling a light source provided in a housing by ventilation, a movableplate which is movable only toward the inside of said housing.
 2. Thelamp house as set forth in claim 1 , wherein said movable plate isattached to the inner side of the side surface of said housing by meansof a hinge provided at the upper part of said movable plate, and whensaid lamp house is not attached to a projector device, said movableplate closes because of its own weight.
 3. The lamp house as set forthin claim 1 , wherein when said lamp house is attached to a projectordevice, said movable plate disposed on the side of an air inlet of saidvent hole opens inwardly upon receiving ventilation from said projectordevice, and said movable plate disposed on the side of an air outlet ofsaid vent hole opens upon insertion of a duct of said projector deviceinto said housing through said air outlet.
 4. The lamp house as setforth in claim 1 , wherein said movable plate is attached to the innerside of the side surface of said housing by means of a hinge provided atthe upper part of said movable plate, when said lamp house is notattached to a projector device, said movable plate closes because of itsown weight, and when said lamp house is attached to the projectordevice, said movable plate disposed on the side of an air inlet of saidvent hole opens inwardly upon receiving ventilation from said projectordevice, and said movable plate disposed on the side of an air outlet ofsaid vent hole opens upon insertion of a duct of said projector deviceinto said housing through said air outlet.
 5. The lamp house as setforth in claim 1 , wherein when said lamp house is attached to aprojector device, said movable plate disposed on the side of an airinlet of said vent hole opens inwardly upon receiving ventilation fromsaid projector device, and said movable plate disposed on the side of anair outlet of said vent hole opens upon insertion of a duct of saidprojector device into said housing through said air outlet, and whichfurther comprises a spring for closing said movable plate, wherein whensaid lamp house is not attached to the projector device, said springcloses said movable plate irrespective of the position of said housing,and said spring attached to said movable plate on the side of the airinlet of said vent hole opens said movable plate inwardly upon receivingventilation from said projector device.
 6. The lamp house as set forthin claim 1 , wherein said movable plate is attached to the inner side ofthe side surface of said housing by means of a hinge provided at theupper part of said movable plate, when said lamp house is not attachedto a projector device, said movable plate closes because of its ownweight, and when said lamp house is attached to the projector device,said movable plate disposed on the side of an air inlet of said venthole opens inwardly upon receiving ventilation from said projectordevice, and said movable plate disposed on the side of an air outlet ofsaid vent hole opens upon insertion of a duct of said projector deviceinto said housing through said air outlet, and which further comprises aspring for closing said movable plate, wherein when said lamp house isnot attached to the projector device, said spring closes said movableplate irrespective of the position of said housing, and said springattached to said movable plate on the side of the air inlet of said venthole opens said movable plate inwardly upon receiving ventilation fromsaid projector device.
 7. The lamp house as set forth in claim 1 ,wherein when said lamp house is attached to a projector device, saidmovable plate disposed on the side of an air inlet of said vent holeopens inwardly upon receiving ventilation from said projector device,and said movable plate disposed on the side of an air outlet of saidvent hole opens upon insertion of a duct of said projector device intosaid housing through said air outlet, and which further comprises: asensor for detecting opening and closing states of said movable platedisposed on the side of the air inlet of said vent hole.
 8. The lamphouse as set forth in claim 1 , wherein said movable plate is attachedto the inner side of the side surface of said housing by means of ahinge provided at the upper part of said movable plate, when said lamphouse is not attached to a projector device, said movable plate closesbecause of its own weight, and when said lamp house is attached to theprojector device, said movable plate disposed on the side of an airinlet of said vent hole opens inwardly upon receiving ventilation fromsaid projector device, and said movable plate disposed on the side of anair outlet of said vent hole opens upon insertion of a duct of saidprojector device into said housing through said air outlet, and whichfurther comprises: a sensor for detecting opening and closing states ofsaid movable plate disposed on the side of the air inlet of said venthole.
 9. The lamp house as set forth in claim 1 , wherein when said lamphouse is attached to a projector device, said movable plate disposed onthe side of an air inlet of said vent hole opens inwardly upon receivingventilation from said projector device, and said movable plate disposedon the side of an air outlet of said vent hole opens upon insertion of aduct of said projector device into said housing through said air outlet,and which further comprises: a spring for closing said movable plate,wherein when said lamp house is not attached to the projector device,said spring closes said movable plate irrespective of the position ofsaid housing, and said spring attached to said movable plate on the sideof the air inlet of said vent hole opens said movable plate inwardlyupon receiving ventilation from said projector device, and a sensor fordetecting opening and closing states of said movable plate disposed onthe side of the air inlet of said vent hole.
 10. The lamp house as setforth in claim 1 , wherein said movable plate is attached to the innerside of the side surface of said housing by means of a hinge provided atthe upper part of said movable plate, when said lamp house is notattached to a projector device, said movable plate closes because of itsown weight, and when said lamp house is attached to the projectordevice, said movable plate disposed on the side of an air inlet of saidvent hole opens inwardly upon receiving ventilation from said projectordevice, and said movable plate disposed on the side of an air outlet ofsaid vent hole opens upon insertion of a duct of said projector deviceinto said housing through said air outlet, and which further comprises:a spring for closing said movable plate, wherein when said lamp house isnot attached to the projector device, said spring closes said movableplate irrespective of the position of said housing, and said springattached to said movable plate on the side of the air inlet of said venthole opens said movable plate inwardly upon receiving ventilation fromsaid projector device, and a sensor for detecting opening and closingstates of said movable plate disposed on the side of the air inlet ofsaid vent hole.
 11. The lamp house as set forth in claim 1 , whereinusing said movable plate disposed on the side of an air inlet of saidvent hole, an air path, in said lamp house, of ventilation received fromsaid projector device is set.
 12. The lamp house as set forth in claim 1, wherein said movable plate is attached to the inner side of the sidesurface of said housing by means of a hinge provided at the upper partof said movable plate, when said lamp house is not attached to aprojector device, said movable plate closes because of its own weight,and using said movable plate disposed on the side of an air inlet ofsaid vent hole, an air path, in said lamp house, of ventilation receivedfrom said projector device is set.
 13. The lamp house as set forth inclaim 1 , wherein when said lamp house is attached to a projectordevice, said movable plate disposed on the side of an air inlet of saidvent hole opens inwardly upon receiving ventilation from said projectordevice, and said movable plate disposed on the side of an air outlet ofsaid vent hole opens upon insertion of a duct of said projector deviceinto said housing through said air outlet, and which further comprises:a spring for closing said movable plate, wherein when said lamp house isnot attached to the projector device, said spring closes said movableplate irrespective of the position of said housing, and said springattached to said movable plate on the side of the air inlet of said venthole opens said movable plate inwardly upon receiving ventilation fromsaid projector device, and using said movable plate disposed on the sideof the air inlet of said vent hole, an air path, in said lamp house, ofventilation received from said projector device is set.
 14. The lamphouse as set forth in claim 1 , wherein said vent hole includes aplurality of air inlets.
 15. A projector device to which a lamp house isattached, said lamp house comprising, at a vent hole for cooling a lightsource provided in a housing by ventilation, a movable plate which ismovable only toward the inside of said housing.
 16. The projector deviceas set forth in claim 15 , comprising a duct for externally dischargingexhaust air from said lamp house, wherein at the time of attachment ofsaid lamp house to said projector device, said duct is inserted intosaid housing through said air outlet to open said movable plate providedat said air outlet toward the inside of said housing.
 17. The projectordevice as set forth in claim 15 , comprising a duct for externallydischarging exhaust air from said lamp house, wherein at the time ofattachment of said lamp house to said projector device, said duct isinserted into said housing through said air outlet to open said movableplate provided at said air outlet toward the inside of said housing, andsaid duct has an exhaust air outlet for discharging exhaust air fromsaid lamp house whose area is larger than a sectional area of each partof said duct and has said exhaust air outlet covered with wire netting.18. The projector device as set forth in claim 15 , further comprisingventilation means for ventilating said lamp house, wherein saidventilation means opens said movable plate disposed on the side of anair inlet of said vent hole toward the inside of said housing by a windpressure caused at the time of ventilation.
 19. The projector device asset forth in claim 15 , comprising: a duct for externally dischargingexhaust air from said lamp house, wherein at the time of attachment ofsaid lamp house to said projector device, said duct is inserted intosaid housing through said air outlet to open said movable plate providedat said air outlet toward the inside of said housing, and ventilationmeans for ventilating said lamp house, wherein said ventilation meansopens said movable plate disposed on the side of an air inlet of saidvent hole toward the inside of said housing by a wind pressure caused atthe time of ventilation.
 20. The projector device as set forth in claim15 , comprising: a duct for externally discharging exhaust air from saidlamp house, wherein at the time of attachment of said lamp house to saidprojector device, said duct is inserted into said housing through saidair outlet to open said movable plate provided at said air outlet towardthe inside of said housing, and said duct has an exhaust air outlet fordischarging exhaust air from said lamp house whose area is larger than asectional area of each part of said duct and has said exhaust air outletcovered with wire netting, and ventilation means for ventilating saidlamp house, wherein said ventilation means opens said movable platedisposed on the side of an air inlet of said vent hole toward the insideof said housing by a wind pressure caused at the time of ventilation.21. The projector device as set forth in claim 15 , further comprising:ventilation means for ventilating said lamp house, wherein saidventilation means opens said movable plate disposed on the side of anair inlet of said vent hole toward the inside of said housing by a windpressure caused at the time of ventilation, and control means forcontrolling operation of said lamp house, wherein said control meansdetermines whether said light source is being cooled according toopening and closing states of said movable plate disposed on the side ofthe air inlet of said vent hole.
 22. The projector device as set forthin claim 15 , comprising: a duct for externally discharging exhaust airfrom said lamp house, wherein at the time of attachment of said lamphouse to said projector device, said duct is inserted into said housingthrough said air outlet to open said movable plate provided at said airoutlet toward the inside of said housing, ventilation means forventilating said lamp house, wherein said ventilation means opens saidmovable plate disposed on the side of an air inlet of said vent holetoward the inside of said housing by a wind pressure caused at the timeof ventilation, and control means for controlling operation of said lamphouse, wherein said control means determines whether said light sourceis being cooled according to opening and closing states of said movableplate disposed on the side of the air inlet of said vent hole.
 23. Theprojector device as set forth in claim 15 , comprising: a duct forexternally discharging exhaust air from said lamp house, wherein at thetime of attachment of said lamp house to said projector device, saidduct is inserted into said housing through said air outlet to open saidmovable plate provided at said air outlet toward the inside of saidhousing, and said duct has an exhaust air outlet for discharging exhaustair from said lamp house whose area is larger than a sectional area ofeach part of said duct and has said exhaust air outlet covered with wirenetting, ventilation means for ventilating said lamp house, wherein saidventilation means opens said movable plate disposed on the side of anair inlet of said vent hole toward the inside of said housing by a windpressure caused at the time of ventilation, and control means forcontrolling operation of said lamp house, wherein said control meansdetermines whether said light source is being cooled according toopening and closing states of said movable plate disposed on the side ofthe air inlet of said vent hole.
 24. The projector device as set forthin claim 15 , further comprising: ventilation means for ventilating saidlamp house, wherein said ventilation means opens said movable platedisposed on the side of an air inlet of said vent hole toward the insideof said housing by a wind pressure caused at the time of ventilation,control means for controlling operation of said lamp house, wherein saidcontrol means determines whether said light source is being cooledaccording to opening and closing states of said movable plate disposedon the side of the air inlet of said vent hole, and a sensor fordetecting opening and closing states of said movable plate disposed onthe side of the air inlet of said vent hole.
 25. The projector device asset forth in claim 15 , comprising: a duct for externally dischargingexhaust air from said lamp house, wherein at the time of attachment ofsaid lamp house to said projector device, said duct is inserted intosaid housing through said air outlet to open said movable plate providedat said air outlet toward the inside of said housing, ventilation meansfor ventilating said lamp house, wherein said ventilation means openssaid movable plate disposed on the side of an air inlet of said venthole toward the inside of said housing by a wind pressure caused at thetime of ventilation, control means for controlling operation of saidlamp house, wherein said control means determines whether said lightsource is being cooled according to opening and closing states of saidmovable plate disposed on the side of the air inlet of said vent hole,and a sensor for detecting opening and closing states of said movableplate disposed on the side of the air inlet of said vent hole.
 26. Theprojector device as set forth in claim 15 , comprising: a duct forexternally discharging exhaust air from said lamp house, wherein at thetime of attachment of said lamp house to said projector device, saidduct is inserted into said housing through said air outlet to open saidmovable plate provided at said air outlet toward the inside of saidhousing, and said duct has an exhaust air outlet for discharging exhaustair from said lamp house whose area is larger than a sectional area ofeach part of said duct and has said exhaust air outlet covered with wirenetting, ventilation means for ventilating said lamp house, wherein saidventilation means opens said movable plate disposed on the side of anair inlet of said vent hole toward the inside of said housing by a windpressure caused at the time of ventilation, control means forcontrolling operation of said lamp house, wherein said control meansdetermines whether said light source is being cooled according toopening and closing states of said movable plate disposed on the side ofthe air inlet of said vent hole, and a sensor for detecting opening andclosing states of said movable plate disposed on the side of the airinlet of said vent hole.